GOST 22518.2-77
GOST 22518.2−77 Lead of high purity. Spectral method of determination of sodium, calcium, magnesium, aluminum, iron, and thallium (with Amendments No. 1, 2, 3)
GOST 22518.2−77
Group B59
STATE STANDARD OF THE USSR
LEAD OF HIGH PURITY
Spectral method of determination of sodium, calcium, magnesium, aluminum, iron, and thallium
Lead of high purity. Spectral method for the determination of sodium, calcium, magnesium, aluminium, iron and tallium
AXTU 1709
Date of introduction 1978−01−01
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR
DEVELOPERS
HP Garcin, L. K. Larina
2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from
3. INTRODUCED FOR THE FIRST TIME
4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS
The designation of the reference document referenced |
Paragraph number section |
GOST 1770−74 |
Sec. 2 |
GOST 6709−72 |
Sec. 2 |
GOST 11125−84 |
Sec. 2 |
GOST 14261−77 |
Sec. 2 |
GOST 14919−83 |
Sec. 2 |
GOST 22518.1−77 |
1.1, 1a.1 |
GOST 22861−93 |
Sec. 2 |
GOST 29169−91 |
Sec. 2 |
5. The expiration time limit is removed by the Resolution of Gosstandart from 08.04.92 377
6. The re-release (Dec 1996) Amendments No. 1, 2, 3, approved in January 1983, June 1987, April 1992 (IUS 5−83, 9−87, 7−92)
This standard specifies the method of spectral determination of aluminium, iron, calcium, magnesium, sodium and thallium in lead of high purity grades S0000, S000, S00 in the range from 5·10to 1·10%.
The method is based on selective chlorination of impurities by pre-alloying of lead with chloride of lead in the crater of the carbon electrode during the heating and subsequent spectral analysis of the prepared samples.
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 22518.1.
(Changed edition, Rev. N 2).
1a. SAFETY REQUIREMENTS
1A.1. Safety requirements — according to GOST 22518.1.
Sec. 1A. (Added, Rev. N 1).
2. APPARATUS, MATERIALS AND REAGENTS
The diffraction type spectrograph DFS-8 (complete installation).
Microphotometer of any type, allowing to measure the density of the blackening of analytical lines.
DC generator, allowing to obtain a voltage of 200−400 V and a current of 20 A.
Hot plate heating according to GOST 14919.
Grinding machine carbon electrodes.
A vertical tubular furnace at 300 W (see drawing).
1 — electrode with the sample; 2 — quartz tube; 3 — the heater 300 W; 4 — furnace body; 5 — pusher; 6 — retainer
Analytical scale with a weighing error of no more than 0.0002 g and a torsion scales with a weighing error of no more than 0.001 g.
Volumetric flasks according to GOST 1770 with a capacity of 100 cm.
Pipettes with a capacity of 1, 2, 5 and 10 cmaccording to GOST 29169−91.
The quartz glasses with a capacity of 50, 100 and 500 cm.
Cup vypaivali quartz with a capacity of 75, 100 and 200 cm.
Chrome-plated tweezers with tips made of PTFE.
Spatulas made of organic glass.
Stand for electrodes made of stainless steel and organic glass.
Knife made of titanium or tantalum.
Jars-plastic or plastic with lids with capacity of 50−100 cm.
Stopwatch.
Electrodes, carbon, high purity of 6 mm in diameter with a crater with a diameter of 4.5 mm, a depth of 10 mm and a crater with a diameter of 4 mm, a depth of 4 mm and contradictory 50 mm length, one end of which is sharpened to a truncated cone.
Spectrographic plates of types I, III or UFS-3 and «pangram».
Distilled water according to GOST 6709, distilled in a quartz distillation apparatus, freshly prepared.
Nitric acid according to GOST 11125 (if necessary, double-distilled in quartz apparatus).
Hydrochloric acid according to GOST 14261, OS.h.
Lead of high purity according to GOST 22861.
Chloride of lead; prepared as follows: 15 g of spectrally pure lead nitrate is dissolved in 150 cmof distilled water. To a solution pour 3 cmof hydrochloric acid. That misses the lead chloride. The solution was decanted. The precipitate is washed twice with 30 cmof distilled water and dried. Chloride of lead is stored in a plastic jar.
Nitrate of lead is prepared as follows: 40 g of lead brand S0000, cut into pieces weighing 50−500 mg, placed in a quartz glass with a capacity of 500 cm(on the glass pre-made label 200 cm), 150 cm pournitric acid, diluted 1:2, and dissolved under heating. To the hot solution add 150 cmof concentrated nitric acid, heated to boiling, in portions of 10−30 cm. The resulting solution with the formed precipitate nitrate of lead is evaporated to a volume of 200 cm. The glass is cooled in running water and the cooled solution was decanted. The precipitate is washed twice with 30 cmof concentrated nitric acid, then dried and heated on the stove until the termination of allocation of vapors .
A solution of sodium chloride containing 0,01 mg of sodium per 1 cm.
A solution of calcium chloride containing 0.01 mg of calcium in 1 cm.
A solution of magnesium chloride containing 0.01 mg per 1 cm.
A solution of aluminum chloride containing 0.01 mg of aluminum per 1 cm.
Ferric chloride containing 0.01 mg of iron in 1 cm.
A solution of chloride of thallium containing 0.01 mg of thallium of 1 cm.
These solutions were prepared by dissolving calculated quantities of metals, their oxides or chlorides in hydrochloric acid.
The resulting solutions diluted with water, transferred into volumetric flasks, adjusted to the mark with water and mix.
Solution 1; prepared as follows: into a measuring flask with a capacity of 100 cmpipetted 10 cmof sodium chloride, calcium, magnesium, aluminum, iron, thallium and bring to mark with water.
Solution 2; is prepared as follows: into a measuring flask with a capacity of 100 cmpipetted 10 cmof solution 1 and bring to mark with water.
Developer metagitnionom.
Fixer is acidic.
Samples comparison.
Note. Allowed the use of devices with photoelectric registration of spectrum and other spectral instruments, materials, reagents and photographic plates, generating accuracy metrics that are regulated by this standard.
(Changed edition, Rev. N 1, 2, 3).
3. PREPARATION FOR ASSAY
3.1. The basis for the preparation of samples comparison serves as lead chloride.
In a quartz Cup with a capacity of 100 cmis placed a portion of chloride of lead and injected the resulting solutions. To prepare samples with a mass fraction of impurities 1·10and 3·10% for every 1 g of chloride of lead, respectively take 1 and 3, seesolution 2. To prepare samples with a mass fraction of impurities 1·10and 3·10% for every 1 g of chloride of lead, respectively take 1 and 3 cmof the solution 1. Allowed to prepare samples in comparisons that contain only certain designated impurities. Depending on the purity of the analyzed lead is allowed to change the content of impurities in the samples. The content of impurities in the basis determined by the method of additions and introduced the amendment in the estimated mass fraction of impurities. For this prepared from samples of the comparison taken on a torsion scale sample mass of 50 mg, and place them in craters of the carbon electrodes (the dimensions of the crater 4x4 mm). The electrodes are pre-fired with the coal contradictable. The spectra are photographed, as specified in sec. 4.
(Changed edition, Rev. N 3).
4. ANALYSIS
4.1. Carbon electrodes with the size of the crater 4,5x10 mm pre-fired in an arc DC power 15 A for 30 sec.
Determination of impurities is conducted by a method of additives. From comparison of samples taken on a torsion scale sample mass of 50 mg, and place them in craters of the carbon electrodes. The first group of electrodes (6 pieces) placed the spectral-pure chloride of lead, the second group of electrodes (6 PCs) sample with a mass fraction of impurities 1·10%, in the third sample with a mass fraction of impurities 3·10% in the fourth sample with a mass fraction of impurities 1·10%. Into the crater of each electrode is placed on top of 1 g of lead in the analyzed pieces. The prepared electrode was heated in a vertical tubular furnace (see drawing). Its pre-include the network through an autotransformer and is heated to a temperature of 500−600 °C. the Pusher is raised to the upper position. The electrode with the sample with tweezers placed in the hole and lowered together with the thrust rod in a lower position. Incubated for 1−2 min. Raise the electrode up, clean stand.
(Changed edition, Rev. N 1, 3).
4.2. For the determination of calcium and magnesium spectra are photographed on the plate of type I when the width of the slit of a spectrograph 0.01 mm. Slit light being a condenser, the intermediate aperture of 3.2 mm.
For the determination of aluminium, iron, thallium and sodium spectra photographed on the plate type III and «Pangram» (for sodium) and a width of slit of the spectrograph is 0.02 mm. the Slit of the spectrograph light two-condenser. Normalisierung condenser 75 installed on the light source at a distance of 100 mm from the slit — 316 mm. exposure Time was 30 s. the Evaporation of the sample and the excitation spectrum to produce an arc DC current of 15 A. the same photographic plates to take pictures of facilities of lead through nine-or three-stage power attenuator for building a characteristic curve of the plate.
(Changed edition, Rev. N 1, 2).
5. PROCESSING OF THE RESULTS
5.1. Spectra of each sample and comparison samples are photographed three times on one record. Using microphotometry on the obtained spectrograms measured blackening of the lines defined elements and minimum darkening of the background to the right and to the left of them. The average of the two measurements of the background accept as true darkening of the background. Build the characteristic curve of photographic plates. It find pochernenija corresponding to the measured values of the logarithms of intensity and then using tables of logarithms or line find and and calculate . The calibration graphs are built in coordinates , where — mass fraction of impurities in the samples of the comparison in percent. Graphics continue to the intersection with the abscissa axis. The numeric value of the received coordinates on the x-axis (mass fraction of impurities) to reduce up to 20 times:
.
Photometric the following analytical lines (wavelength in nanometers):
sodium |
Na I 588,99 |
||
calcium |
Sa II 396,85; I 422,67 | ||
magnesium |
Mg I 285,21 | ||
iron |
Fe I 302,0 | ||
aluminium |
Al I 308,21 | ||
thallium | Tl I 276,78. |
The relative standard deviation characterizing the convergence of the results of parallel measurements and the reproducibility of the results does not exceed 0,1. The final result of the analysis be the arithmetic mean of results of two parallel measurements obtained on two photographic plates.
(Changed edition, Rev. N 1, 2, 3).
5.2. Discrepancies in the results of two parallel measurements () and the results of two tests () at a confidence probability of 0.95, should not exceed the permissible differences given in table.
Mass fraction of impurities, % |
The discrepancy between the results of parallel measurements , % |
The discrepancy between the results of two tests , % |
5·10 |
2·10 |
2·10 |
1·10 |
0,3·10 |
0,4·10 |
2·10 |
0,6·10 |
0,8·10 |
4·10 |
1·10 |
1·10 |
8·10 |
2·10 |
3·10 |
1·10 |
0,3·10 |
0,4·10 |
Permitted discrepancies for the intermediate mass fraction of impurities is calculated by the formula
;,
where is the arithmetic mean of the results of parallel measurements;
— the average of the two results of the analysis.
(Changed edition, Rev. N 3).